in vitro GERMINATION AND ORGANOGENESIS IN THREE VARIETIES OF COMMON BEAN (Phaseolus vulgaris L).

Abstract

Mexico is the center of origin for common bean (Phaseolus vulgaris L.), the most widely cultivated legume in the country. This species presents great genetic variability, which makes it valuable against climate change in different production systems. In vitro plant tissue culture techniques are tools that support the multiplication of valuable and scarce material, but still have to face the recalcitrance of the species. The objective of this research was to evaluate the in vitro germination and organogenesis of common bean varieties Flor de Mayo, Jamapa and Peruano. For in vitro germination, disinfection treatments with commercial sodium hypochlorite (20 and 30 %) and hydrogen peroxide (H₂O₂) (0-3 % v/v) were evaluated at different immersion times (0 to 4 h). In shoot induction, explants such as node and cotyledonary axis, embryonic axis and cotyledon were used, grown in Murashigue and Skoog (MS) and B5 media supplemented with 6-benzyladenine (BA) 72 μM. BA and thidiazuron (TDZ) were also tested. During shoot multiplication, node and cotyledonary axis were planted on MS medium supplemented with BA and TDZ (54, 72 and 90 μM). For elongation, the MS medium was evaluated with two levels of inorganic salts (50 and 100 %). Sodium hypochlorite was more effective for disinfecting Flor de Mayo seeds, while 20 % was sufficient for the other two varieties. The use of H₂O₂ did not alter the germination process and negatively impacted phenological development. On average, 1.4 shoots per explant were obtained for Flor de Mayo and Peruano in MS medium, and 1.4 in B5 medium for Negro Jamapa. In multiplication, an average of 18 shoots were produced in two varieties. In elongation, the plant length increased in MS medium 100 % in the three varieties.